The purpose of this study was to examine the effect of regular exercise training on insulin sensitivity in adults with type 2 diabetes mellitus ( T2DM ) using the pooled data available from randomised controlled trials. In addition, we sought to determine whether short-term periods of physical inactivity diminish the exercise-induced improvement in insulin sensitivity. Eligible trials included exercise interventions that involved ≥3 exercise sessions, and reported a dynamic measurement of insulin sensitivity. There was a significant pooled effect size ( ES ) for the effect of exercise on insulin sensitivity ( ES, –0.588; 95% confidence interval [CI], –0.816 to –0.359; P < 0.001 ). Of the 14 studies included for meta-analyses, nine studies reported the time of data collection from the last exercise bout. There was a significant improvement in insulin sensitivity in favour of exercise versus control between 48 and 72 hours after exercise ( ES, –0.702; 95% CI, –1.392 to –0.012; P=0.046 ); and this persisted when insulin sensitivity was measured more than 72 hours after the last exercise session ( ES, –0.890; 95% CI, –1.675 to –0.105; P=0.026 ). Regular exercise has a significant benefit on insulin sensitivity in adults with T2DM and this may persist beyond 72 hours after the last exercise session
